Anti-HER2 monoclonal antibody trastuzumab remains the only targeted therapy of gastric carcinoma based on histopathological predictive diagnostics used in current routine clinical practice. In the Czech Republic only the adenocarcinomas with HER2 immunohistochemical score of 3+, together with HER2 amplification detected with in situ hybridization are indicated for treatment with trastuzumab.
There has been recent progress in our understanding of the molecular biology of gastric cancer, the role of its tumor microenvironment and vascular supply points to PD-1/PD-L1 and VEGFR2 as possible future targets of targeted therapy. Unfortunately, the interpretation of the results of pharmacological studies, as well as establishing new algorithms of predictive diagnostics are complicated by insufficient molecular stratification of tumors enrolled in the study groups.